sub state {
  pop=~/^(A[KLRZ]|C[AOT]|D[CE]|FL|GA|HI|I[ADLN]|K[STY]|LA|M[ADEINOST]|
+N[CDEHJMVY]|O[HKR]|PA|RI|S[CD]|T[NX]|UT|V[AT]|W[AIVY])$/
}
[download]

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

Your subroutine will accept "AK\n" as a state. Fixing that takes it to 125. But I can beat that with the following 122 character solution (which is what I was trying to figure out when I posted my first):

sub state{
$_[0]=~/^\w\w\z/&&grep/$_[0]/,'WVTNHINMSCORIDCAKSDE WIALAR MNCTX NVAZ'
+,'FLGAILKTKYMAMDMEMIMOMTNDNENJNYOHOKPAUTWAWY'=~/../g
}
[download]

OTOH I can improve your idea down to 119:

sub state {
pop=~/^([CGILPVW]A|[CKUV]T|[HRW]I|A[KLRZ]|CO|DC|DE|FL|I[DLN]|KS|KY|M[A
+DEINOST]|N[CDEHJMVY]|O[HKR]|SC|SD|TN|TX|WV|WY)\z/
}
[download]

Your first one can go down to 121:

sub state{
  grep$_[0]eq$_,'WVTNHINMSCORIDCAKSDE WIALAR MNCTX NVAZ'=~/(?=(\w\w))/
+g,'FLGAILKTKYMAMDMEMIMOMTNDNENJNYOHOKPAUTWAWY'=~/../g
}
[download]

... or you could have just taken the easy route by converting the && into an &.

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

And 2 characters less by group the first letters too:

sub state {
    pop=~/^(A[KLRZ]|C[AOT]|D[CE]|I[ADLN]|K[STY]|M[ADEINOST]|N[CDEHJMVY
+]|O[HKR]|S[CD]|T[NX]|V[AT]|[GLP]A|[HR]I|FL|UT|W[AIVY])$/
}
[download]

--bwana147

Have fun,
Carl Forde

Not so, the regex returns matches in pairs, ie:

@list = 'foobarbazo' =~ /../g;  # sets @list to ('fo','ob','ar','ba','
+zo')
[download]

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

Aaahhhh, I see. That's what I get for not testing it first.

Have fun,
Carl Forde

KT.

Kentucky is supposed to be KY, but that list was pulled from a mapping that had to account for several mistakes. Sorry. (Similarly Quebec is PQ, but is often mistakenly written as QC.)

BTW the US state abbreviations also include GU, PR and VI.